Good manufacturing processes, concern for the environment, and changes in environmental practices and regulations all have created additional needs in handling waste fluids after manufacturing and cleaning operations. These needs are especially important when water based mixtures containing pollutants such as greases, oils, soaps, heavy metals, road film and carcinogens collect during the operation. Whereas in the past it was acceptable merely to dump such waste liquids in the ground or in sewer systems, current good manufacturing practices and environmental laws and regulations now severely discourage and/or prohibit such practices. Although very laudable in intent, the result can be very costly, especially to small manufacturers and to business operators who must use substantial quantities of water in their operations, as for example the cleaning and degreasing of manufactured parts, such as metal products, and the cleaning and maintenance of vehicles and other machines that by their nature will shed greases and oils and often detergents and road film with the wastewater.
An example of a wastewater treatment apparatus is disclosed in U.S. Pat. No. 5,582,680 (issued Dec. 10, 1996) by Vankouwenberg. Vankouwenberg discloses a compact, self-contained apparatus for treating wastewater containing, as impurities and pollutants, various non-volatile (the boiling point of water) fluids such as greases, oils, road films, carcinogens and detergents. The apparatus comprises a reservoir for collecting the wastewater with automatic shut-off protection at high and low fluid levels, a heating means surrounding the reservoir to heat the wastewater admixture in the reservoir to boil off the water, a collection means to draw off the non-volatile fluids from the water reservoir during operation of the apparatus, and an automatic refill/shutdown means of the apparatus. Although a very useful, economical and operable apparatus, Vankouwenberg, as with other techniques, may not necessarily be the most efficient use of heat. Moreover, for certain applications, particular impurities sometimes may cause the wastewater to foam excessively when the water reaches its boiling temperature, thus requiring a temporary shut down to remove the excess foam. Each shut down of the apparatus can be a loss of time, labor and heat.
It is therefore an object of this invention to provide an apparatus for treating wastewater wherein efficiency of heat use is a priority.
It is another object of the invention to provide an apparatus that is highly efficient in wastewater treatment.
It is another object of this invention to provide an improved apparatus for treating wastewater by evaporation and for recovery of non-volatile fluids and other contaminants, using conventionally available materials and components that are easy and safe to operate and provide an efficient use of heat.
It is yet another object of this invention to provide an apparatus that may recycle purified water after treatment of the wastewater.